Phenotypic typing and epidemiological survey of antifungal resistance of species detected in clinical samples of Italian patients in a 17 months' period.

INTRODUCTION

Yeast pathogens are emerging agents of nosocomial as well as community-acquired infections and their rapid and accurate identification is crucial for a better management of high-risk patients and for an adequate treatment.

METHODS

We performed a retrospective review of 156 yeast isolates collected during a 17 months' period of regular clinical practice at the Microbiology Department of San Camillo Hospital in Treviso, Italy and analyzed by the traditional culture-based method combined with matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS).

RESULTS

Out of all the samples collected MALDI-TOF MS was able to characterize with a MT score ≥1.7 (accurate result at species level) 12 different yeast and yeast-like species from 140 samples: (63.7%), (13.6%), (6.5%), (5.7%), (2.1%), (2.1%), (2.1%), (1.4%), (0.7%), (0.7%), (0.7%), (0.7%). Susceptibility testing toward seven common antifungal agents showed a characteristic MIC distribution of isolates for echinocandins: particularly we noticed that 72% and 46% of showed an MIC value close to clinical breakpoint as defined by EUCAST, respectively for anidulafungin and micafungin.

CONCLUSION

Accurate identification of microorganisms and the study of their antifungal susceptibility allow to understand the epidemiology of a particular area, permitting the choice of the most appropriate early antifungal treatment.